This invention relates generally to a transfer sheet and the apparatus and method used to form the transfer sheet. More particularly, this invention relates to a transfer sheet formed by using a digitally controlled color printer.
It is known to decorate textiles by printing patterns in various colors by a suitable printing method, such as the silk screen process. In a typical silk screen printing process, each individual color is applied to a sheet of silicon paper. An adhesive layer is applied thereover. Thereafter, the transfer sheet is pressed against the fabric with heat being applied to effectuate the transfer of the colored pattern from the transfer sheet to the fabric. Heretofore, color copiers have been used to print color images on a thermoplastic coated transfer paper. The color images printed on the paper are then transferred by heat impression to cotton textiles. A typical digitally controlled color printer is an electrophotographic printing machine or an ink jet printing machine.
In an electrophotographic printing machine, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a digitally controlled light image corresponding to the desired print being reproduced. Exposure of the charged photoconductive member selectively dissipates the charge thereon in the irradiated areas to record an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the document being printed. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the electrostatic latent image is developed with dry developer material comprising carrier granules having toner particles adhering triboelectrically thereto. However, a liquid developer material may be used as well. The toner particles are attracted to the latent image forming a visible toner powder image on the photoconductive member. After the electrostatic latent image is developed with toner particles, the toner powder image is transferred to a sheet. Thereafter, the toner powder image is heated to permanently fuse it to the sheet.
In forming a transfer sheet which will be used to create a color print on another substrate, it is necessary to use a color electrophotographic printing machine or a color ink jet printing machine. Color electrophotographic printing machines produce a color print by forming yellow, magenta, cyan, and black color separations. There are many variations of color electrophotographic printing machines. For example, there is a single pass color electrophotographic printing machine and a multi-pass electrophotographic printing machine. In one type of a single pass electrophotographic printing machine, successive different color images are developed on the photoconductive belt in superimposed registration and transferred to the sheet in registration with one another. Each image is formed and developed on the photoconductive belt in a single cycle of operation. In another type of single pass electrophotographic printing machine, successive photoconductive members transfer different color images to an intermediate belt or to the sheet, in registration with one another. When an intermediate belt is used, the composite image is transferred from the belt to the sheet. Alternatively, in a multi-pass electrophotographic printing machine, successive different color images are on the photoconductive belt in successive cycles. Thus, it requires multiple cycles to form the composite multicolor image on the photoconductive belt. This composite image is then subsequently transferred to the sheet and fused thereto.
Multi-pass and single pass printing machines are described in U.S. Pat. No. 5,666,612, issued to Beachner, et al., on Sep. 9, 1997, the relevant portions thereof being hereby incorporated into the present application. Still another specific type of electrophotographic printing machine which is adapted to produce color prints is a tandem printing machine. In a tandem color printing machine, successive color engines are positioned along a sheet path. Each color engine includes a photoconductive drum which is exposed to digitally controlled single color light images. These single color light images are developed by the appropriately colored toner particles. After development, the toner powder image is transferred to the sheet advancing on a belt, or alternatively to an intermediate belt. Successive engines of this type are positioned along the belt with each engine forming a different color toner powder image which is transferred to the common sheet, in superimposed registration with one another, to form the multicolor image thereon. The resultant composite multi-color toner image is then fused to the sheet. A multi-color printing machine of this type is sold by the Xerox Corporation under the Model No. DocuColor 40. Finally, there are various types of color ink jet products which produce color prints. For example, Tektronix Corporation Model Phaser 840 utilizes solid ink which is melted, and, using piezoelectric print heads, sprayed onto a sheet in superimposed registration to form a color print. Color printing machines of the type heretofore described produce prints having a resolution ranging from about 400 to about 600 dots/inch (dpi). These prints approach photographic quality. However, none of these printing machines form a white underlayer for the color image. This is essential when transferring the color pattern to a non-white fabric or textile.
Thus, it is apparent that it would be highly desirable to be able to utilize a color electrophotographic printing machine having high resolution to produce transfer sheets which may be used to decorate articles such as fabrics. Heretofore, there have been various attempts to utilize electrophotographic printing machines, however, all of these attempts have resulted in hybrid systems, i.e., the use of two different printing technologies to achieve the final transfer sheet, with a white colored underlayer. The following disclosures appear to be relevant:
The following is a discussion of the foregoing, which are incorporated hereby by reference, and which may be relevant to the present invention:
WO-97/21867 discloses a sheet of paper or heat resistant plastic sheet coated with a thin release layer of silicone or polyolefin. A first transparent elastomer layer is configuratively printed by silk screen printing on the silicone or polyolefin surface, and, on top of the elastomer surface, a one or multi-colored pattern is printed with a digitally controlled color printer. On top of the colored pattern, a second transparent elastomer layer is configuratively printed again by silk screen printing, and, in the same manner, a white-pigmented elastomer layer is printed on the second elastomer layer. Uppermost, a heat activatable, thermoplastic polymeric glue layer is applied thereon.
U.S. Pat. No. 4,685,984 describes a process for transferring indicia from paper to a fabric backing member. An indicia carrier layer of tacky, contact adhesive is bonded to the backing member by a thermoplastic elastomer layer. A combination of webs involved in the transfer process is supported through the steps, including water wash and at least the initiation of fusing, by a temporary support layer of heat resistant, water-impervious polymers, having a non-silicone high release coating. Heat and pressure are applied through this layer to firmly fuse the thermoplastic elastomer layer along with the carrier layer and the indicia to the backing member prior to stripping of the temporary support layer. The firm fusing and release action established by the non-silicone high release coating prevent distortion or destruction of any portion of the indicia during the stripping step.
U.S. Pat. No. 4,773,953 describes a method for creating personalized, creative designs or images on a fabric using a personal computer system. The design is first created by hand on the monitor screen of the computer system. This design is then printed onto a heat transfer sheet. The design is then ironed onto the fabric. The design may be an image, such as a picture, created by a video camera.
In accordance with one aspect of the present invention, there is provided a transfer sheet including a carrier sheet. A colored pattern is printed on a surface of the carrier sheet using at lease one digitally controlled color printer. A layer of white colored material is printed over at least the colored pattern using the digitally controlled printer.
In still another aspect of the present invention, there is provided an apparatus for transferring a colored pattern from a carrier sheet to a final support material. The apparatus includes at least one digitally controlled color printer for printing the colored pattern on a surface of the carrier sheet. The printer prints a white colored material over at least the colored pattern.
Yet another aspect of the present invention is a method of transferring a colored pattern from a carrier sheet to a final support material. The method includes using at least one digitally controlled printer to print the colored pattern on a surface of the sheet and to print a white colored material over at least the colored pattern.